From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Request for comparative technical information on the 4 1/4 litre Bentley with the new overdrive gearbox.
| Identifier | ExFiles\Box 83\3\ scan0079 | |
| Date | 6th September 1938 | |
| 200. SECRET. S/W Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} Cx{Major Len W. Cox - Advertising Manager}7/KW6.9.38 We are very anxious to have some information on the relative merits of the current type 4¼ litre Bentley and the overdrive gearbox type now coming into production, particularly as regards performance. For instance, from my experience of one of the overdrive Bentleys which I tried some months ago, when I took comparative acceleration figures between the standard 4¼ and the overdrive Bentley, the latter was superior in all respects in acceleration from a standing start no matter what gear was used. I feel sure you will be able to give us a very useful and interesting comparative table of acceleration figures, and this will be of considerable importance to us in convincing people that the performance really is superior to the old model. It would also be helpful to us to know what is the true top speed on the level. From a chart that I once saw I believe the theoretical top gear speed of the overdrive model at 4500 revs is 110 m.p.h., but I also know that the car will not attain that speed on the level. Other interesting technical information which would help us would be the comparative maximum speeds on the gears and the comparative gear ratios themselves. We should also like to know the technical benefits to be derived from the more important improvements, such as - The fixed shutters and thermostatic water control, as compared with the old arrangement ; The full benefits that you claim from the fitting of smaller wheels with larger tyres ; The best way to describe the improvements in the steering; Your chief claims to the merits of the overdrive box, and (contd) | ||